Clinical Anatomy of the European Hamster 
5.9 FEMALE GENITAL ORGANS 
The reproductive organs of the female include 
the ovaries; oviducts; uterus with uterine horns 
and cervix, and the vagina (Fig. 5-71). Externally, 
the female hamster also has a quite prominent 
clitoris as well as a bulb of the vestibule. 
5.9.1 OVARY 
The ovaries (ovaria) have two functions: produc- 
ing ova and synthesizing the hormones estradiol 
and progesterone. Each lies dorsolateral to the most 
caudal quarter of the corresponding kidney, be- 
tween the kidney and the dorsal abdominal wall 
(Figs. 5-71, 5-72). Only rarely do the ovaries lie 
at the level of the caudal pole of the respective kid- 
neys. Depending on the nutritional condition of the 
hamster and the season of the year, the ovaries are 
embedded in varying amounts of adipose tissue. In 
many cases, only the ventral side of the ovaries are 
free from fat; in especially well-nourished ham- 
sters, the ovaries are totally surrounded by fat (Fig. 
5-72). Each ovary weighs about 26 mg (Tables 4, 
6, 8, 18, 18a). In general, the variance in weight of 
the ovaries is greater during the seasonal cycle than 
during the estrus cycle (Fig. 5-73). The maximum 
diameter is about 5 mm (Zuchner, 1975). 
On the ventral side of the ovaries, the knobbed, 
grayish-red surface shines through a pale, glossy 
bursa (bursa ovarica), which has the shape of a 
longitudinal oval and surrounds the entire ovary. 
The bursa is compressed laterally so that the tubal 
extremity of the ovary {extremitas tubaria) is ori- 
ented cranially and the uterine extremity {extremi- 
tas uterina) caudally, while each surface — lateral 
or medial — is oriented ventrolaterally or dorso- 
medially. The ovaries are invested by the meso- 
varium which originates from the broad ligament 
{lig. latum uteri). At the ovarian hilus {hilus 
ovarici), the ovarian bursa and ligament of the 
ovary {hg. ovarii proprium) are inserted; the latter 
is relatively well developed and runs to the lateral 
angle of the uterus at a point just dorsal to the uter- 
ine horns. 
The ovary consists of a peripheral cortex (zona 
parenchymatosa) and a central medulla (zona vas- 
culosa). The cortex is surrounded by connective 
tissue (tunica albuginea), the outer surface of which 
is covered by a simple cuboidal epithelium. The 
cortex contains follicles (folliculi ovarici) at various 
stages of maturation (Fig. 5-74), which are sur- 
rounded by the stroma. In the cortex, intact or 
involuting corpora lutea, corpora albicantia, atretic 
follicles and corpora atretica are found. The central 
medulla is composed of reticular fibers, elastic fibers 
and connective tissue cells and contains numerous 
vessels. The medulla also contains numerous inter- 
stitial cells which appear epitheloid. During hiber- 
nation a pronounced decrease in the number of 
mature follicles occurs, and corpora lutea are almost 
completely lacking (Fig. 5-75) (Zuchner, 1975). 
This effect is not observed in nonhibernating ani- 
mals during winter (Zuchner, 1975). Females kept 
under standard laboratory conditions (i.e., nonhi- 
bernating) demonstrate the highest ovarian activity 
(most numerous mature follicles and corpora lutea) 
from February to the end of May. Females that 
hibernate during winter develop the same degree of 
functional activity at the beginning of May (Zuch- 
ner, 1975). 
5.9.2 Oviducts 
The oviducts (tuba uterina) are present as wind- 
ing, narrow tubes which run caudally from the 
ovary to the pointed uterine horns, with which they 
merge at the ostium uterinum tubae. The ovarian 
end of the oviduct is funnel-shaped and broadens 
into the infundibulum (infundibulum tubae uter- 
inae) which surrounds the caudolateral ovarian 
pole and opens freely into the abdominal cavity. 
The infundibular funnel includes finger-like pro- 
jections {fimbriae tubae), some of which are orien- 
ted along the lateral ovarian wall. 
The oviduct is lined by a simple columnar epithelium which is also 
in distinct papilliform folds (Fig. 5-77). 
5.9.3 Uterus 
All ova are transmitted to the uterine hOrns 
where they adhere to the wall of the tube before 
passing to the uterus; if unfertilized, they degener- 
ate with extrusion of the debris through the uterus 
and vagina. The uterus is bipartite, composed of an 
undivided body (corpus uteri), and the uterine horns 
(cornua uteri) (Fig. 5-76). Caudodorsal to the uri- 
nary bladder, the uterine horns separate, diverging 
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